Marine propeller shaft brake



April 19, 1966 B. H. MOYE 3,246,724

MARINE PROPELLER SHAFT BRAKE Filed June 24, 1963 I N VEN TOR.

BENJAMIN H. MOYE ATTORNEY United States Patent Ofilice 3,246,724 MARINE PROPELLER SHAFT BRAKE Benjamin H. Moye, 66 Beach St., Warren, R.I. Filed June 24, 1963, Ser. No. 290,024 4 Claims. (Cl. 1924) My present invention relates to marine engines and drives and more particularly to a novel brake on the marine drive shaft.

The principal object of the present invention is to provide a braking mechanism for a marine drive shaft for preventing rotation of the propeller shaft and propeller when the transmission mechanism is in neutral position.

Another object of the present invention is to provide a braking mechanism for a marine drive shaft which utilizes the power of the engine for operating the brake.

A further object of the present invention is to provide a braking mechanism for a marine drive shaft which can be operated automatically by the transmission lever mechanism.

A further object of the present invention is to provide a braking mechanism for a marine drive shaft which can be operated manually or under power.

With the above and other objects and advantageous features in view my invention consists of a novel arrangement of parts more fully disclosed in the detailed description following in conjunction with the accompanying drawings and more particularly defined in the appended claims.

In the drawings,

FIG. 1 is a front elevation of a brake mechanism hook up embodying my present invention.

FIG. 2 is a side view thereof taken on line 2-2 on FIG. 1.

FIG. 3 is a top plan View, partly in section of the pressure valve mechanism.

Inboard marine engines, especially of small craft such as fishing boats, are always faced with the problem of residual rotation of the drive shaft when the transmission mechanism is in neutral position. The drive shaft has a tendency to continue to rotate and slowly turn the propeller. This can be a great disadvantage in certain instances. Some boats, for example when sneaking up on a swordfish, cut their engines completely to prevent the lines from fouling in a rotating propeller. Also, when maneuvering a boat to a dock side, it is sometimes important that the propeller be at a complete standstill. Any residual rotation will cause damage to the dock or the boat or both.

The present invention is designed to provide a braking mechanism for holding the propeller shaft at a standstill when the transmission mechanism is in neutral position. The device of the present invention is designed to operate on the available construction and power of the marine engine and its transmission mechanism and is versatile so that it can be made to operate automatically or manually at the will of the operator of the boat.

Referring more in detail to the drawings illustrating my invention, FIG. 1 illustrates a front elevation of a marine engine and drive shaft construction. In this view, the marine engine mounting frame 10, is mounted on side blocks '11 and the transmission 12 is connected by a plate 13 to the transmission shaft 14. The plate or plates 13, one on the transmission 12 and the other mounted at the end of the shaft 14 are bolted together as illustrated 3,246,724 Patented Apr. 19, 1966 U-shape around the plates '13 as illustrated in FIG. 1, and is provided with a lining 16. For .the purposes of holding the shaft from rotating when the transmission is in neutral position, it is not necessary that the brake lining '16 be as full as illustrated and it is possible to obtain results with the lining only extending a one fourth of a circle around the plates 13. It is also contemplated that the pressure of the brake band '15 and its lining 16 on the plates 13 be the minimum required to retain the shaft in non-rotating position.

A supporting bar 17 is mounted transversely across between the blocks 11 as shown in FIG. 1 and extending transversely just above the plates 13. One end of the band 15 is pivotally attached to a lever arm 18 having its other end pivotally mounted on the bar 17 as shown in FIG. 1. The other end of the band '15 is also pivotally mounted to a much longer lever arm 19 which is pivoted at 20 to the bar '17. This pivot is so placed that the longer portion of the lever arm 19 extends above the bar 17. Pivotal movement of the lever arm 19 will thus cause a tightening of the band 15 and its lining 16 around the plates 113.

It is contemplated that the braking action provided by the lever 19 be just strong enough to frictionally hold the shaft 14- fr-om rotating when the transmission 12 is in neutral position. Should anything go wrong and the brake be in on position when the transmission is placed into forward or reverse, the shaft 14 will rotate as usual causing only a frictional wearing on the lining 16. This must be the case, otherwise a stronger brake will cause breakage, burning and other possible damage to the transmission linkage. Actually, with the transmission in neutral position, only a light pressure of the brake band 15 is necessary to prevent rotation of the shaft 14. Movement of the lever 19 for applying or releasing the brake mechanism can be accomplished in several ways. The simplest form is the attachment of a Bowden cable to the top end of the lever 19 and bringing the other end of the cable to the dashboard of the boat so that when the engine is placed in neutral the operator can then pull the cable and put the brake on to prevent rotation of the shaft. Conversely, the operator'must release the cable to release the brake before placing the transmission into forward or reverse speeds.

In the form illustrated in FIGS. 1, 2 and 3, the brake is set by means of the power available in the engine. This can be done by utilizing the pressure of the engine or the vacuum pressure of the engine or both. In the form illustrated a cylinder 21 is mounted so that its piston rod 22 pivotally engages the upper end of the brake operating lever 19. A collar 23 surrounds the piston rod and a and form the means for disconnecting the engine when it is removed for replacement or repair without disturbing the drive shaft and propeller. These plates are normally about one half to one inch in thickness and are utilized for the purposes of the present invention as a brake drum.

A metal brake band 15 is positioned in a spring 24 is positioned between the collar 23 and the end of the cylinder 20 to normally urge the piston rod 22 to the right in FIG. 1 which in turn urges the lever 19 into brake release position. In other words, when there is no power applied to the cylinder 20, the brake will be in releasing position. The other end of the cylinder is connected by a flexible hose 25 to a short pipe 26 extending rearwardly from a plate 27 having an opening 28 therethrough. At the front of the plate 27 a bar 29 is pivoted at 31 at its lower end. The bar 29 is provided at its front with a short pipe 31 attached by a flexible hose 32 to the vacuum part of the engine. The bar 29 is pro vided with an opening 33 in alignment with the pipe 31 and flexible hose 32 and also in alignment with the opening 28 in the plate 27 when the bar is in the vertical position illustrated in FIGS. 2 and 3.

Thus with the bar 29 in the vertical position illustrated in FIGS. 2 and 3, the vacuum pressure of the engine passes through the flexible hose 32, pipe 31, opening 33 in the bar 29. opening 28 in the plate 27, pipe 26, flexible hose 25 to the cylinder 29. This causes the piston in the cylinder and the piston rod 22 connected to it to move to the left in FIG. 1 against the action of the spring 24 and apply the brake mechanism. In this position it is noted that a rod 34 is pivotally connected to the bar 29 at one end and its opposite end is pivotally connected to the transmission lever 35. In some constructions the bar 34 may be replaced with a chain and a spring arrangement for the return action. When the lever 35 is moved into the dotted line positions 36 and 37 for putting the engine in forward or reverse speeds, the movement of the lever 35 will cause pivotal movement of the plate 29 to throw the openings 28 and 33 out of alignment. In either direction the opening 33 will now face an unpunctured portion of the plate 27 to completely block the vacuum from the engine. This will also expose the opening 28 and allow air to enter the pipe 26 and flexible hose 25 to the cylinder 20 allowing the spring 24 to move the piston rod 22 to the right in FIG. 1 to release the brake. With the above hook up it thus is obvious that when the lever 35 is pushed into forward or reverse speeds the brake is automatically released. Whereas, if the lever 35 is moved into the neutral position illustrated in FIG. 2 the brake is automatically put on. Should there be a failure in any of the mechanisms, the transmission and engine will be strong enough to easily rotate the shaft 14 against the action of the brake without breaking any of the parts and merely causing a slight wear on the brake lining 16.

The above construction can also be used where a positive pressure is being used in the cylinder 20 instead of the vacuum pressure illustrated. The cylinder can also be used with a combination of vacuum and positive pressures in a two way construction. However this will require a more complicated valve arrangement than that illustrated.

I have thus described a simple and easy method of applying a braking action to the drive shaft of a marine vehicle when the transmission is placed in neutral position. The construction is simple and easy to assemble and can be economically applied to any marine engine. In some instances the coupling plates 13 may be in an awkward position for attaching the brake levers above it. In such cases a separate split pulley or drum can be attached directly to the shaft 14 further along the shaft. Either way the device utilizes the existing engine power and is simple and easy to operate. Other advantages of the present invention will be readily apparent to a person skilled in the art.

I claim:

1. In a marine engine having a transmission, a shift lever for said transmission, and a drive shaft extending from said transmission, a brake for said drive shaft comprising a plate mounted on said shaft and forming a brake drum, a brake band partially surrounding said brake drum, one end of said band having a fixed pivotal connection, a lever mounted above the other end of said band, the other end of said band being pivotally connected to one end of said lever, and means for pivoting said lever to apply said brake 'When said engine transmission is in neutral position to prevent rotation of said shaft, said pivoting means including a fluid cylinder, a piston rod extending from said cylinder and pivotally connected to said lever, and means for reciprocating said piston rod to apply or release said brake, valve means for controlling the operation of said cylinder, said valve means including a tube extending from said cylinder to a fixed member, a second tube extending from the engine to a movable member, said members holding said lines in alignment in one position, and means for moving said movable member to apply or release said brake.

2. In a marine engine having a transmission, a shift lever for said transmission, and a drive shaft extending from said transmission, a brake for said drive shaft comprising a plate mounted on said shaft and forming a brake drum, a brake band partially surrounding said brake drum, one end of said band having a fixed pivotal connection, a lever mounted above the other end of said band, the other end of said band being pivotally connected to one end of said lever, and means for pivoting said lever to apply said brake when said engine transmission is in neutral position to prevent rotation of said shaft, said pivoting means including a fluid cylinder, a piston rod extending from said cylinder and pivotally connected to said lever, and means for reciprocating said piston rod to apply or release said brake, valve means for controlling the operation of said cylinder, said valve means including a tube extending from said cylinder to a fixed member, a second tube extending from the engine to a movable member, said members holding said lines in alignment in one position, and means for moving said movable member to apply or release said brake, said cylinder being operable by the vacuum pressure of said engine.

3. In a marine engine having a transmission, a shift lever for said transmission, and a drive shaft extending from said transmission, a brake for said drive shaft comprising a plate mounted on said shaft and forming a brake drum, a brake band partially surrounding said brake drum, one end of said band having a fixed pivotal connection, a lever mounted above the other end of said band, the other end of said band being pivotally connected to one end of said lever, and means for pivoting said lever to apply said brake when said engine transmission is in neutral position to prevent rotation of said shaft, said pivoting means including a fluid cylinder, a piston rod extending from said cylinder and pivotally connected to said lever, and means for reciprocating said piston rod to apply or release said brake, valve means for controlling the operation of said cylinder, said valve means including a tube extending from said cylinder to a fixed member, a second tube extending from the engine to a movable member, said members holding said lines in alignment in one position, and means for moving said movable member to apply or release said brake, said pivoting means being controlled by the movement of the transmission lever.

4. In a marine engine having a transmission, a shift lever for said transmission, and a drive shaft extending from said transmission, a brake for said drive shaft comprising .a plate mounted on said shaft and forming a brake drum, a brake band partially surrounding said brake drum, one end of said band having a fixed pivotal connection, a lever mounted above the other end of said band, the other end of said band being pivotally connected to one end of said lever, and means for pivoting said lever to apply said brake when said engine transmission is in neutral position to prevent rotation of said shaft, said pivoting means including a fluid cylinder, a piston rod extending from said cylinder and pivotally connected to said lever, and means for reciprocating said piston rod to apply or release said brake, valve means for controlling the operation of said cylinder, said valve means including a tube extending from said cylinder to a fixed member, a second tube extending from the engine to a movable member, said members holding said lines in alignment in one position, and means for moving said movable member to apply or release said brake, said cylinder being operable by the vacuum pressuze of said engine, said pivoting means being controlled by the movement of the transmission lever.

References Cited by the Examiner UNITED STATES PATENTS 1,578,459 3/1926 Miller et al 188-77 1,784,354 12/1930 Haussmann 1924 1,862,871 6/1932 Tremolada 192-4 1,878,944 9/1932 Lombard.

(Other references on following page) UNITED STATES PATENTS 2,725,128 11/1955 Martin 19Z-4 Games X 3,003,606 10/1961 Hindmarch 192-4 Miller 192-4 Kliesrath 192 4 DAVID J. WILLIAMOWSKY, Prlmary Examine]. Morse 192 4 5 DON A. WAITE, Examiner.

Bergman 251-301 X B. WYCHE, Assistant Examiner. 

1. IN A MARINE ENGINE HAVING A TRANSMISSION, A SHIFT LEVER FOR SAID TRANSMISSION, AND A DRIVE SHAFT EXTENDING FROM SAID TRANSMISSION, A BRAKE FOR SAID DRIVE SHAFT COMPRISING A PLATE MOUNTED ON SAID SHAFT AND FORMING A BRAKE DRUM, A BRAKE BAND PARTIALLY SURROUNDING SAID BRAKE DRUM, ONE END OF SAID BAND HAVING A FIXED PIVOTAL CONNECTION, A LEVER MOUNTED ABOVE THE OTHER END OF SAID BAND, THE OTHER END OF SAID BAND BEING PIVOTALLY CONNECTED TO ONE END OF SAID LEVER, AND MEANS FOR PIVOTING SAID LEVER TO APPLY SAID BRAKE WHEN SAID ENGINE TRANSMISSION IS IN NEUTRAL POSITION TO PREVENT ROTATION OF SAID SHAFT, SAID PIVOTING MEANS INCLUDING A FLUID CYLINDER, A PISTON ROD EXTENDING FROM SAID CYLINDER AND PIVOTALLY CONNECTED TO SAID LEVER, AND MEAN FOR RECIPROCATING SAID PISTON ROD TO APPLY OR RELEASE SAID BRAKE, VALVE MEANS FOR CONTROLLING THE OPERATION OF SAID CYLINDER, SAID VALVE MEANS INCLUDING A TUBE EXTENDING FROM SAID CYLINDER TO A FIXED MEMBER, A SECOND TUBE EXTENDING FROM THE ENGINE TO A MOVABLE MEMBER, SAID MEMBERS HOLDING SAID LINES IN ALIGNMENT IN ONE POSITION, AND MEANS FOR MOVING SAID MOVABLE MEMBER TO APPLY OR RELEASE SAID BRAKE. 